BRITISH WARBLERS
of the secondary sexual characters. If this were really true, the weaker males would thus be eliminated and an appeal to the law of battle unnecessary. Thirdly, that it is almost inconceivable that such terribly severe struggles should have been developed if they were not of some direct benefit to the victorious individuals; and, lastly, that in the event of such a further selection taking place, cases of males possessing a territory and yet not attaining to reproduction ought, as already pointed out, to be of not uncommon occurrence. And, having regard to the very meagre evidence upon which is founded that part of the sexual selection theory which would refer the victory to those males that were enabled to excite the females in the highest degree, and considering, too, the very strong evidence in favour of the question of reproduction being decided by a law of battle, it is difficult to resist the conclusion that the latter is the means by which the weaker individuals have been debarred from transmitting their defects to the race.
The fighting of the females, if it can be shown to be characteristic of a number of species, will have an important bearing on this whole question. In discussing the theory of sexual selection in the life of the Grasshopper Warbler, I stated as one of my principal objections to that theory that the ultimate production of the most healthy and most beautiful offspring by the selection of certain males is, without a corresponding selection amongst the females, impossible, and of the existence of such a selection in any form there is no evidence; and upon this point I see no reason to alter my views. In fact, further consideration seems to me to add to rather than detract from the force of this objection. For it must be borne in mind that what we are in reality aiming at is the maintenance of the strength of the species, and in thus stating my objection I wished to make it clear that in order to attain this end an elimination of the weaker females is as necessary as an elimination of the weaker males. Strength and beauty cannot be separated, and even if it were ultimately proved that there
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